This invention relates to a radio communication apparatus for receiving a selective call signal, which includes a message. The radio communication apparatus may be a radio-paging receiver, a transceiver, or the like although description will mainly be directed to the radio-paging receiver.
A radio-paging system comprises a plurality of radio-paging receivers and a plurality of base stations each for transmitting a selective call signal. A radio-paging receiver of the type described includes a receiving circuit for carrying out a receiving operation of selectively receiving the selective call signal specific to the apparatus. The receiving circuit produces a received signal whenever the receiving circuit receives the selective call signal specific thereto.
The selective call signal may include a message and the radio-paging receiver may include a memory and a visual display device. In this event, the radio-paging receiver receives the massage as a received massage in the receiving circuit, stores the received massage in the memory as a stored massage, and visually displays the stored massage on the visual display device by reading the stored massage out of the memory in response to an instruction of a user or a possessor thereof. Inasmuch as selective call signals including respective messages are successively received in the receiving circuit of the radio-paging receiver, the memory thereof stores received messages as stored or accumulated messages. In the radio-paging receiver of the type described, inasmuch as the memory has a finite or limited storage capacity, it is necessary to delete an unnecessary one in the stored messages from the memory when the storage capacity of the memory is insufficient. Under the circumstances, it is convenient or helpful to carrying out deletion of the unnecessary one in the stored messages by the user before a remaining usable storage capacity in the memory is running out.
In order to cope with this, a radio-paging receiver or an individual selective call receiver is published in Japanese Examined Patent Publication of Tokkou No. Hei 3-8,607 or JP-B 3-8,607 (which will be herein called a first reference) on Feb. 6, 1991 which is hereby incorporated herein by reference. The radio-paging receiver according to JP-B 3-8,607 accumulates the total number of characters for the stored massages as an accumulated character number and visually displays the accumulated character number on the visual display device.
On the other hand, in order to easily handle the radio-paging receiver, it is important for the radio-paging receiver that how to read the stored massages out of the memory without difficulty. From this point of view, proposal is made about another radio-paging receiver wherein each part of each stored massage is visually displayed page by page on the visual display device. In order to find a desired page, the user or the possessor repeatedly carries out a message progressive switching operation indicative of advancing the page to be displayed to the next page and a message back feed switching operation indicative of returning the page to be displayed to the previous page.
In the above-mentioned conventional radio-paging receivers, the user must operate the radio-paging receiver to select a suitable one of the accumulated messages to delete it when the remaining usable storage capacity of the memory decreases. In addition, each of the stored messages comprises a plurality of characters and the stored messages have lengths of characters that are generally different from one another. That is, a received message has a short length of characters while another received message has along length of characters. However, in the conventional radio-paging receivers, inasmuch as only the accumulated character number is visually displayed on the visual display device, it is difficult for the user thereof to determine that deletion of which message is effective in securing the remaining usable storage capacity of the memory so far as the user sees or watches contents on the visual display device. In order to resolve this problem, those skilled in the art will devise a method for visually displaying the character number for each of the stored messages on the visual display device with numeric representation. In other words, the method visually displays the character number for each of the stored messages on the visual display device with digital representation. However, in such a method, the user must determine large or small of a series of the character numbers for the stored messages that are visually displayed on the visual display device and results in being inconvenient to the user or the possessor thereof.
In addition to the above-mentioned problem, the conventional radio-paging receivers are disadvantageous in that a reading operation for the accumulated massages is inconvenient to the user or the possessor thereof. More specifically, many time and a lot of switching operations are necessary for the users or the possessors in a case of reading the accumulated messages in the conventional radio-paging receivers. This is because the users or the possessors must go through procedures of carrying out an indication of a page for each stored message and of finding an indication of the desired page.